Given that the HS stack in the top-bolt is logarithmic there is a damping curve associated with the shape of that shim set.

Various high-shaft-speed events will activate more of that shim set than others.

By 'initial' I meant the lower rates of deflection on that HS set, (not beginning of travel). Initial in a physical deflection sense rather than a velocity/pressure/travel sense.

IMO there's a lot of goodness to be gained up there. Ryan Marmont does a billet double-adjuster shock head for PDS shocks and the difference it makes is astounding. NOST made a replacement top-bolt for a while, it was good too.

With both P15 and 20, I (78kg) felt they blew through the first 2/3 of the stroke and then went too stiff. They were good for sand whoops but horrible on a MX track IMO.

I get the idea, trying to get the variable ratio in a PDS a bit closer to a linkage, I just preferred the straight-rate after a few tuning tips from Bluerider. P springs aren't that weird that a good tuner can't get them working really well. I rode a 525 that Terry did with a P20 and it was superb.

Well, it looks like the previous owner has set the spring preload with a hammer and a screwdriver with the bike sitting on the ground as the threads on the shock body are sheared and I had an absolute prick of a time trying to loosen the preload nut to get the spring off.

I was able to find a 2nd hand shock on gumtree from an identical bike and have been provided with a stock spring and a 95kg spring.

__________________It pumps one way and then it pumps the other...
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